Box-stacking mechanism



Aug. 4, 1959 J. c. HUISKING BOX-STACKING MECHANISM Filed May 12, 1954 5 Sheets-Sheet 1 a 1 34 mm a m 5! T NM 4 4 IE Aug. 4, 1959 J. c. HUISKING 2,897,949

BOX-STACKING MECHANISM Filed May 12, 1954 5 Sheets-Sheet 2 I l l i l l i J's 9.84 INVENTOR.

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BOX-STACKING MECHANISM Filed May 12. 1954 5 Sheets-Sheet 3 INVENTOR. JOSEPH C. m/sz/A/e,

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I 9 o l W W 4 2 -4 x 4 4 m g 0D 5 9 4 x x a a a w 4 J a I l 3 2 United States Patent O BOX-STACKING MECHANISM Joseph C. Huisking, Pomona, Calif., assignor to Pomona Foundry, Inc., Pomona, Calif., a corporation of California Application May 12, 1954, Serial No. 429,256

24 Claims. (Cl. 19835) This invention relates to a stacking mechanism for handling objects such as boxes and containers and more particularly relates to a compact, simply constructed and arranged mechanism for forming a stack of said objects in a novel manner.

The stacking mechanism of this invention contemplates the accumulation and movement of spaced boxes to be stacked in a single vertical pathway. Boxes are intermittently introduced to said pathway at a receiving station and may be carried along said pathway in spaced relation in one direction until a selected number of boxes to be stacked are accumulated. Once such a selected number of boxes have been so accumulated, the direction of movement of the spaced boxes is reversed so that all of said boxes return along said single pathway. The lowermost box comes to rest upon a discharge conveyor means which extends across said pathway and the succeeding boxes are stacked thereupon and upon one another in successive relation. After a stack has been so formed, the discharge conveyor means is actuated. for moving the stack formation away from said pathway.

Prior proposed stacking mechanisms have included the stacking of boxes by downward movement of boxes; however, such prior stacking mechanisms have included relatively complex and space-taking construction. Such prior stacking mechanisms known to me have included endless elevator means comprising spaced parallel pathways wherein objects are fed to an upwardly moving section of said elevator means, carried across the top thereof, and then moved downwardly along a parallel downwardly moving section of the elevator means, a stack being formed on the downwardly moving side of the elevator means. Such prior construction occupies approximately twice as much space as the stacking mechanism of this invention because of the two parallel moving sections of the endless elevator means.

The primary object of this invention is to disclose and provide a novel improved stacking mechanism for boxes and containers or the like wherein a single straight vertical zone or pathway is utilized for accumulating and later moving boxes into stack formation.

An object of this invention is to disclose and provide .a novel stacking mechanism wherein a single pathway for moving boxes to be stacked is provided and wherein :said boxes may be moved in one direction for accumuletting a selected number of boxes to be stacked and .then moved in the reverse direction along the same path- &way for stacking said boxes.

Another object of this invention is to disclose and provide a stacking mechanism employing a single vertical pathway'for stacking of boxes wherein a receiving station for introducing boxes to said pathway may be provided intermediate ends of said pathway or at one end of said pathway.

Still another object of this invention is to form a stack of boxes by movement thereof in a single vertical pathway and wherein the aggregate stack load is distributed 70 along the moving means for said boxes in said pathway.

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A further object of this invention is to disclose and provide a stacking mechanism wherein improved means are provided for transferring or feeding boxes to a receiving station in said pathway.

A still further object of this invention is to disclose and provide for a stacking mechainsm as above mentioned relatively simply constructed and arranged boxsupporting means for engaging said boxes for movement along said pathway.

This invention contemplates reciprocally moving a selected number of boxes along a single vertical pathway for first accumulating and then depositing said boxes one on top of the other to provide a quick and efficient means for stacking said boxes.

A still further object of this invention is to disclose and provide a stacking mechanism as above mentioned wherein stack alignment means are actuated upon movement of said boxes in stack-forming direction to squeeze said boxes into lateral alignment before and during the stackforming operation.

A still further object of this invention is to disclose and provide simply constructed box support elements on an elevator chain means for supporting a box and for automatic disengagement therewith during stack forming.

This invention contemplates a novel stacking mechanism for boxes and the like wherein said boxes may be fed to said stacking mechanism at the top thereof and said boxes may beyaccumulated and stacked while moving in one direction. The invention contemplates novel box-feeding means including the employment of fluid pressure means for rapidly advancing a box into the receiving station. The invention also includes a novel feed means for rapidly advancing a box, depositing the box on an elevator chain means, and then retracting the box support of the feed means from beneath the deposited box before said box moves downward in the pathway provided by the stacking mechanism.

These and other objects and advantages of this invention will be readily apparent from the following description of the drawings in which an exemplary embodiment of this invention is shown.

In the drawings:

Fig. 1 is a diagrammatic view illustrating feeding and elevation of boxes to accumulate a selected number of boxes to be stacked.

Fig. 2 is a diagrammatic view illustrating stack-forming operation and discharge of a formed stack from the stacking mechanism.

' Fig. 3 is a front view of a stacking mechanism embodying this invention.

Fig. 4 is a side view of the stacking mechanism shown in Fig. 3.

Fig. 5 is a fragmentary enlarged view illustrating arrangement and action of boxes and box-supporting means during the stack-forming operation.

Fig. 6 is a transverse sectional view taken in the plane indicated by line VIVI of Fig. 5.

Fig. 7 is a fragmentary enlarged view of a box transfer and feed mechanism used with the stacking mechanism shown inFig. 1.

Fig. ,8 is a horizontal sectional view taken in the planes indicated by line VIIIVIII of Fig. 7.

Fig. 9 is a fragmentary sectional view taken in the vertical' plane indicated by line IVIV of Fig. 7.

Fig. 10 is a fragmentary top front view of the stacking mechanism shown in Fig. 1 and illustrating the stack alignment means in operation.

Fig. 11 is a fragmentary top view of the feed means for the stacking mechanism.

Fig. 12 is a fragmentary side view of a modification of the box feed means.

Fig. 13 is a top view of Fig. 12.

Fig. 14 is a fragmentary side view of a modification showing a top feed means for boxes.

Referring particularly to Figs. 1, 2 and 4, there is illustrated an exemplary stacking mechanism embodying this invention which generally includes a feed conveyor means indicated at 15 for moving a plurality of boxes to be stacked in a horizontal path toward a stack mechanism frame means generally indicated at 16. The conveyor means 15 moves said boxes first to a transfer feed means 17 which advances boxes intermittently to a receiving station-R in said frame means 16. The frame means 16 provides a single vertical pathway for movement of boxes received at receiving station R upwardly and in spaced relation until a selected number of boxes to be stacked have been accumulated above receiving station R. Elevator or box-moving means 18 for supporting said boxes in such spaced relation are carried by frame means 16. The elevator means may be reversed in direction of movement so that said plurality of accumulated boxes may be returned downwardlyalong said single pathway to a stack-forming zone S normally located below and including the receiving station R. A stack discharge conveyor means 19 extends into said stack-forming zones and across the lower portion of said vertical pathway. The lowermost box carried by the box elevator means is deposited on the extended portion of the discharge conveyor means and as the elevator means continues to carry the boxes downwardly, they are stacked one upon the other.

Alignment'means 20 are carried by frame means 16 to positively exert a pressure inwardly against sides of said boxes when the elevator means commences its downward movement so that said boxes are squeezed into lateral alignment prior to and during stack forming. After the stack is so formed on the discharge conveyor means, control means are actuated whereby the formed stack is moved out of said pathway by the discharge conveyor means and thence to a selected destination.

For purposes of clarity and explanation, the several means mentioned above which comprise the stack mechanism are described in detail separately.

Feed conveyor means The feed conveyor means 15 (for advancing boxes 22 or the like from a suitable source to said stacking mechanism may comprise continuously moving spaced parallel endless horizontal chain means 23 (Figs. 8 and 11). Chain means 23 may be supported at the feed end by suitable sprockets (not shown) and at the discharge end of said convoyer means by suitable sprockets 24. The sprockets 24 are carried by a transverse shaft 25 supported by suitable bearings carried on longitudinally extending frame members 26. The frame members 26 may be supported by transversely spaced frame members 27 carried by stack frame means 16.

The feed convoyer means 15 also includes longitudinally extending parallel side rails 28. Means are provided on said side rails for causing advancing boxes to stop or hesitate before being fed to the transverse feed means -17. One side rail 28 may carry a longitudinally and inwardly extending guide strip 29 to slidably contact an advancing box and fixed at one end to said rail as at 30 and biased inwardly by a spring means 31 carried by said rail adjacent the other end of said strip 29. The guide strip 29 thus causes a box to move laterally during its advancement so that the opposite lead corner of a box will be directed against a rearwardly facing stop shoulder 32 provided on the opposite rail 28. A box 22 is thus held against advancement to the transfer feed means until it is correlated in time with the stacking mechanism.

Means for pushing a box out of engagement with stop shoulder 32 for further advancement toward the stack shoulder 32 and normal to the conveyor means 15. Cylinder means 33 includes a laterally movable piston rod 34 arranged to contact the side of a box adjacent to stop shoulder 32 to push the box therefrom. The cylinder and piston means 33 is actuated in timed relation with other portions of the stacking mechanism as later described.

Transfer feed means The transfer feed means 17 is arranged to successively receive boxes pushed from said shoulder 32 and to advance one box at a time into receiving station R in timed relation with the box elevator means 18.

The transfer feed means may comprise a pair of longitudinally extending spaced parallel endless chains 40 lying between discharge end portions of the chain means 23 of the feed conveyor means 15. The chains 40 at each end are carried by spaced sprockets 41 mounted upon a transversely extending axle 42 supported at its ends in bearing means 43 carried by longitudinally extending frame members 44. The frame members 44 may also support transverse members 27. One of the shafts 42 may be extended beyond a frame member 44 to carry a drive sprocket 45 connected to a chain drive 46 (Figs. 4 and 8). The drive chain means 46 for the transfer feed means may be connected through suitable sprocket and gear means 67 to a drive motor means 68. The motor 68 may be supported upon a suitable mounting bracket 69 carried by the frame means 16 "below and at one side of the transfer feed means. The chains 40 may carry transversely aligned pairs of box-engaging lugs 47, said aligned pairs of lugs being spaced longitudinally a distance greater than the length of a box so as to accommodate a box therebetween. While only two pairs of lugs are illustrated, more or fewer pairs of lugs may be employed depending upon the length of a box and the endless chains 40.

The transfer feed means also includes means for supporting and holding a box in receiving station R in the vertical pathway in such a manner that the box elevator means 18 may readily engage bottom margins of a box. Such means may include a longitudinally extending, rigid, box support bar 49 of inverted T-section movable between the endless chains 40. The bar 49 is provided a length substantially greater than the length of a box to be carried thereby. The top edge of a central longitudinally extending web 50 of the bar 49 may lie slightly below the horizontal plane defined by the top faces of the top lays of the endless chains 40. At the front end of the bar 49 adjacent to the receiving station R an upstanding longitudinal positioning box element 51 is provided for contact with the front end face of a box and to limit advancement of said box in the re-' ceiving station.

piston means 33 carried by the conveyor frame adjacent The bar 49 is supported and guided by a support member 52 carried by transverse members 27 and extending therebetween. The member 52 includes at each end inwardly turned guide elements 53 which define grooves 54 for slidably receiving cross web 55 of bar 49. Adjacent the front box positioning element 51 the bar 49 may be provided with laterally extending ribs 56 adapted to abut as at 57 the front edge of member 5230 as to limit rearward'movement of the bar 49.

The bar 49' is normally biased into retracted position by a coil spring 57connected at one end as at 58 to the rear end of bar 49 and connected at its other end as at 59 to a cross member 60 of the frame of the feed conveyor means 15. Forward movement of the bar 49 may be limited by a suitable stop lug 61 adjustably carried by the cross web 55 of the bar 49 and adapted to abut the rear end face of member 52.

Lateral positioning of a box on the transfer feed means is achieved by a longitudinally extending guide strip member 63 secured at one end as at 64 to an extended rail 28 of the feed conveyor means and biasedinwardly at its front end by a coil spring 65. A box which is thus pushed off stop Shoulder 32 and is advanced by the transfer means is guided by said guide strip 63 into substantially longitudinal alignment with the feed transfer means prior to entry of the box into the receiving station. Thus the box is initially properly laterally positioned so that the box elevator means 18 will properly engage bottom margins of said box.

The transfer feed means is actuated by control means to be described later. It will be readily apparent that the transfer feed means will advance and support a box into the receiving station and hold a box at said receiving station until the box is lifted therefrom by the box elevator means 18,

Stack frame means Frame means 16 defines a vertical single pathway for reciprocal movement of boxes therealong to accumulate a selected number of boxes to be stacked and to form a stack.

The stack frame means 16 may be made of any suitable structural section and frame construction and includes parallel vertical fabricated columns 75 laterally spaced apart a selected distance to permit boxes to be moved vertically therebetween. The columns 75 may be interconnected at their lower ends by a suitable base plate 76 and at their upper ends by suitable spaced top cross members 77. Each column 75 may comprise front and rear upstanding elongated laterally disposed plates 7 8, each of said plates having secured thereto as by welding a pair of transversely spaced inwardly facing channel members 79. Each channel member 79 may terminate in spaced relation to the top and bottom of column 75 and the spaced channel members on each plate 78 may provide guide grooves for inboard and outboard lays of each of a pair of an endless elevator chain means 80. The outboard channel members 79 may be interconnected along their length by spaced horizontal members 81. The inboard channel members are not intercoimected so as to provide a vertically extending open space 82 for movement of box-supporting means therealong.

Extending rearwardly from the spaced columns 75 and affording support and rigidity to said columns may be an open frame work construction generally indicated at 84 and comprising vertical columns 35 interconnected by spaced transverse frame members 86 and spaced longitudinal members 87, said longitudinal members 87 being secured to the columns as by welding. The rearwardly extending frame construction 84 may include bottom transverse and longitudinal members 88 and 39 respectively. The frame construction 84 as illustrated may provide the supporting structure for the transfer feed means and the end sprockets 2d of the feed conveyor means as previously described.

It should be noted that the spaced columns 75 provide at a point intermediate their length and opposite to the transfer feed :means a receiving opening for station R and at the front of said frame means the spaced columns provide a stack discharge opening 9t through which a formed assembled stack may readily be moved.

Box elevator means The box elevator means is operable to move boxes along said pathway between columns 75 as by lifting and supporting said boxes in spaced relation to accumulate a selected number for stacking and then lowering said boxes to form a stack in said pathway. Boxes are received at station R and the elevator means is intermittently driven in timed relation to the feed means as later described.

The box elevator means 18 comprises, in addition to the pairs of elevator chain means 3-9 in each column 75, ver tically spaced pairs of sprockets 95 for supporting said chain means adjacent the top and bottom of columns 75. Each pair of sprockets 95 may be carried by a longitudinally extending shaft 96 which may be journalled in 6 bearing means 97 mounted on front and rear column plates 78.

Means for driving said elevator chain means in the spaced columns 75 in correlated relation may comprise an extension 98 provided on each of the top shafts 96, said extension having a driving connection in Well-known manner to a cross shaft 9 supported by suitable bearings 1% carried by longitudinal members 87 of the frame construction 84. The shaft 99 extends outwardly beyond one side of the frame means 16 to carry a sprocket 1111 which is driven by a drive chain 162 having connection at its other end to a sprocket 103 driven by a reversible elevator motor means 104. The motor means 104 may be carried by a pair of laterally extending motor mount ing members 105 which may be secured as by welding to longitudinal members 87 of the frame construction 84 above the feed means 17.

The pairs of elevator chain means Eitl disposed within columns 75 may carry a plurality of horizontally aligned, inwardly extending juxtaposed box-supporting means. 110. The box support means 111 are spaced apart on said chain means 80 a distance greater than the height of a box to be stacked. Each box support means includes a pair of triangularly shaped side members 111 each freely pivotally connected at a bottom corner thereof to the inner face of a chain means 89 as at 112 and normally having one edge vertical and alongside the chain means. The pivotal connection 112 preferably comprises an extended pivot bolt or pin 113 which pivotally connects links of the chain. The side members 111 carried by each pair of chains 89 are interconnected by a longitudinally extending cover member 114- of metal sheet material secured to said side members as by welding. The cover member provides a normally horizontal flat seating plate 115 providing a flat horizontal top surface for contact with bottom margins of a box. The cover member also includes a downwardly and outwardly inclined integral plate 116 providing an inclined wedge surface 117 adapted to engage edges of a lower adjacent box to cause disengagement of said box support means with the box supported thereby as later described.

Each box support means 11% is provided with position ing or stop means to limit pivotal movement thereof. The positioning means may comprise a normally vertically disposed lug 118 integrally formed at the outboard edge of each side member 111, said lug being provided abutting engagement as at 119 with said chain means.

Each side member 111 may also be provided with a lug 120 integrally formed adjacent the downwardly inclined edge thereof to limit outward movement of said box support means by engagement with said chain means when said box-supporting means are moved out of boxsupporting position during a stack-forming operation.

It will be readily apparent that said box support means 111? are normally urged into box-supporting position by gravity because of the free pivotal connections at the lowermost corners of the side members 111. Thus when the box elevator means are being intermittently driven by the motor means 104; in an upward direction, the box-supporting means 110 are in position to engage as at 121 bottom side margins of a box held in receiving station R by the box-supporting bar 49. As the box elevator means carries a box upwardly, the box support means are held in position to engage a box by limit lugs 118 and the slidable contact of chains 80 against walls of the channel sections 79.

In continuous downward movement 'of the elevator means (Fig. 5) in the stack-forming zone S, the inclined wedge surface 117 will slidably contact the top side edge of a box stopped therebelow and the box support means will be slidably urged outwardly from between the stopped box and the downwardly moving box by the inclined surface 117. When the box support means is fully retracted from between adjacent boxes it will readily slide downwardly along side surfaces of boxes already stacked upon one another. At the bottom of the columns 75 sufiicient clearance is provided to allow the box support means to pass "beneath the bottom ends of the chain means 80. Upon reversal of the direction of movement of the elevator means to an upward direction, each box support means falls into box support position as it enters the pathway and is ready to receive a box thereon when the receiving station R is reached.

Discharge conveyor means The discharge conveyor means 19 may be of any well-known type of conveyor means for moving a stack to a selected destination. In this example a pair of endless discharge conveyor chains 125 are arranged in spaced parallel longitudinally extending relation. The chains 125 extend across and beneath the single pathway defined between the columns 75 in the stack frame means 16. One end of the discharge chain means 125 (Fig. 4) may be supported by spaced sprockets 126 carried by a horizontal shaft 127 supported in bearing means 128 carried by mounting plates behind columns 75. The other end of the endless chains 125 may be carried by sprocket means (not shown) in similar manner.

The upper lays of chain means 125 may be supported by longitudinally extending upwardly facing channel members 129, said channel members being supported by transverse angle iron members 130 secured to columns 75. Thus immediately beneath the stacking station the discharge conveyor means are afforded a vertically nonyielding support.

The discharge conveyor means are arranged to receive and stop movement of the lowermost box of an accumulation of boxes carried between the columns 75 when the boxes are moved downwardly. Normally the discharge conveyor means are inoperative and are actuated when a stack has been formed by stacking the boxes one upon the other in the stacking zone. The means for actuation of the discharge conveyor means at that time will be described later.

Alignment means The alignment means 20, to urge as by squeezing the accumulated boxes in their downward movement into lateral alignment as a stack is being formed, may comprise a pair of vertically extending angle section guide members 135 mounted to cover or enclose the front and rear inboard corners of each guide column 75. Each guide member 135 presents a vertical fiat surface 136 lying parallel to the pathway and adapted to be urged against sides of boxes carried between the columns 75.

Means for simultaneously urging guide members 135 inwardly into said engagement with box sides may comprise vertically spaced links 137 pivotally connected to each guide member as at 138 and to the associated column 75 as at 139. The upper end of each guide member 135 may be pivotally connected as at 146 to an upwardly and slightly inwardly extending link 141, the links for each guide member being pivotally connected at upper ends at 142 to crank arms 143. The other end of each crank arm 143 is fixedly connected to a shaft 144 journalled in bearing means 145 supported on top cross member 77.

The laterally spaced crank arms 143 may be actuated by a transversely disposed double-acting lluid operated cylinder means 146 carried by the top of the frame construction. A piston rod 147 of the cylinder means 146 is connected'by linkage means to each crank shaft 144 for simultaneous rotation thereof in opposite directions by a pivotal connection at 148 at the piston free end to a short lever 149 which is fixedly connected at its'other end to the opposed adjacent shaft 144. Also pivotally'connected at 148 is a downwardly inclined laterally extending connecting 'lever 150 which is pivotally connected at 151 to a downwardly inclined le- '8 ver 152 fixedly connected to the other shaft 144. It will be apparent that upon reciprocal movement of the piston rod 147 the linkage means including levers 149, 152 and will cause opposite rotation of shafts 144 so as to drive the pivotally hung guide members 135 inwardly into squeezing relation with respect to boxes carried by the elevator means.

The alignment means is actuated upon downward movement of the boxes so that said boxes are urged into alignment prior to-and as they are stacked in the stacking station and upon the end portion of the discharge conveyor means 19.

Control means and operation The control means may comprise a plurality of limit switch means mounted on frame means in suitable manner for actuation of various parts of the stacking mechanism in order that boxes may be fed intermittently to the pathway and that control of said boxes during acomplete stacking operation may be correlated in timed relation. It is understood any suitable automatic control means may be employed and the control means generally described hereinafter is exemplary only.

For example, the reversible motor means 104 which drives the elevator chain means 80 is electrically con nected for initially starting of the stacker to move the chain means 80 upwardly.

Boxes are placed upon the feed conveyor means 15 by any suitable method for advancement to the stacking mechanism. The feed conveyor means is continuously driven to advance said boxes. An advancing box is guided by guide strip 29 against stop shoulder 32 which stops advancement of the box, the feed conveyor means continuing to move beneath the stopped box.

Movement of a box against shoulder 32 depresses switch arm 161 of box feed switch 160. Under the condition where the elevator means is upwardly operative by the motor means 104 the circuit to the switch is closed and operative to cause piston 34 to be actuated to push a box off shoulder 32 so that said box may be advanced by the conveyor means 15 onto the transfer feed chain means. A box thus advanced onto the transfer feed means contacts switch arm 162 of a safety limit switch means 163 which. then temporarily locks open the circuit energizing the limit switch means 160 and renders inoperative piston 34 so that a succeeding box stopped by shoulder 32 will not be fed onto the transfer feed means for further advancement. Later, switch means 160, upon downward movement of the elevator chain means, is also locked open by other means as later described so that upon stacking, the feed of boxes is stopped.

Further advancement of the box causes a box side to contact a switch arm 164 of a transfer feed switch means 165 to actuate transfer feed motor means 63 for driving the transfer feed chain means 40. Advancement of the box by a box-engaging lug 49 of the transfer chain means 44 causes the front face of the box to abut against upstanding lug 51 on bar 49 so that the bar is advanced with and supports the box as the box enters receiving station R between columns 75. Forward movement of bar 49 causes a switch-contacting lug 166 provided on the tail end of bar 49 to contact a'switch arm 167 of a switch means 168 carried below the bar which causes the elevator means 80 to move upwardly. It will be apparent that switch arm 167 cannot contact lug 166 until the box is fully positioned in receiving station R.

At approximately the same time a second spaced boxengaging lug 47, in its movement along the lower lay of transfer chain means 40, contacts a switch arm 170 for energizing a second transfer feed switch means 171 for causing the feed chains. 40 to stop so that a succeeding box pushed off shoulder 32 will not be advanced into the receiving station.

Upon the elevator means 80 moving upwardly by energization of switch means 168, a box-supportingmeans 1'10' engages bottom surfaces of the box positioned in the receiving station to lift the box vertically. The box is lifted until an inwardly extending switch arm 172 is engaged by one of the pins pivotally mounting the lower adjacent box-supporting means. Arm 172 actuates elevator stop switch means 173 carried by the frame means below the receiving station and stops the elevator means with the adjacent lower box-supporting means 110 in box-receiving position; that is, slightly below the plane in which a box is advanced by bar 49 into receiving station R.

When a box on the transfer feed means clears switch arm 162 of safety switch means 163, the switch means 160 is unlocked and operative so that the following box Will be pushed olf shoulder 32 for advancement by the feed conveyor means upon the transfer feed means. This succeeding box is advanced to receiving station R and elevated by the elevator means by actuation of the various switch means as above described. Boxes are thus successively and intermittently fed to the stacking mechanism and accumulated therein on the said pathway in spaced relation until a selected number of boxes to be stacked is reached.

Control and determination of the selected number of boxes to be stacked along said pathway may be conveniently provided by a plurality of vertically spaced limit switch means 177 mounted on one of the columns 75. Each switch means 177 is operable through an associated rotatable rod 176 extending between front and rear plates 178 of a column 75 and carrying a switch arm 175. The switch arm 175 extends between chain means 80 for contact with an extended portion of one of the pivot pins on each box-supporting means 110. Normally all but one of the switch means 177 are de-energized, the one energized switch means 177 being the one selected by the operator for determining and limiting the number of boxes to be stacked.

Upon contact of the arm 175 of a selected energized switch means 177 by a pivot pin of a box support means 110, the elevator motor 104 is caused to reverse its direction to move the elevator chain means downwardly. The motor means 104 is so electrically connected to the box feed switch means 160 that upon reversal of motor means 104 by closing of a selected switch means 177 the box feed switch means 160 is held de-energized so that boxes will not be pushed off shoulder 32 and will not be fed to the stacking mechanism during downward movement of the elevator chain means. Thus, while the accumulated spaced boxes are being stacked one upon the other, the feeding of the boxes to the stacking path is stopped and the transfer feed means are inoperative.

Means which may, if desired, de-energize all of the various switch means for operating the stacking mechanism to prevent the elevator means 80 from over-running at the top thereof may comprise a safety switch means 178 carried at the top of the stack frame means. The safety switch means 178 includesa depending contact arm 179 seated against a transverse bar 180 downwardly biased by pin and spring assemblies 181 carried by top frame cross members 77. Contact of a top box with bar 180 actuates the safety switch means 178 which results in de-energization of selected switch means in the stacking mechanism to prevent further operation thereof.

Reversal of the elevator chain means 80 to move the boxes downwardly also causes the alignment means 20 to be actuated inwardly so as to squeeze and guide the spaced accumulated boxes into lateral alignment. The loweimost end box of the accumulated, spaced boxes moves downwardly until it is seated upon the end portion of the discharge conveyor means which extends across the bottom of said stacking pathway. Continued movement of the elevator means downwardly causes the boxes to be successively stacked one upon the other in the manner heretofore described. During the entire downward movement of the boxes and during stacking the alignment means 20 exerts an inwardly directedv pressure against sides of the boxes so that thy will be accurately laterally aligned when stacked.

The elevator means 80 continues downward movement after a stack has been formed until an element 186 carried by the elevator means 80 contacts a switch arm 187 which is connected to a switch means 189 by a transverse rotatable rod 188 carried by a column 75. Upon contact of switch arm 187 the switch means 189 stops the elevator motor means 104. It should be noted that the switch means 189 is carried by column 75 adjacent to the receiving station R so that downward movement of the elevator means 80 will permit stacking of two boxes if so desired.

When the lowermost box is seated upon the end portion of the discharge conveyor means, said lowermost box contacts and depresses a longitudinally extending switch bar 183 lying between the discharge conveyor chains. Switch bar 183 is associated with a switch means 184 for energizing a time-delay means (not shown) for causing actuation of the discharge conveyor means 19 after sufficient time has elapsed to permit the maximum number of boxes which may be accumulated in the pathway to be formed into a stack. After the stack has been formed, the discharge conveyor means is actuated and the formed stack is moved outwardly from the pathway along the discharge conveyor means for a selected distance. When 7 the switch bar 183 is released, the motor means 104 is electrically connected for raising the elevator means 80 upwardly.

When switch bar 183 is first depressed by the lowermost box the transfer means is inoperative because the chain means is moving downwardly and switch 160 is locked as heretofore described. The first box of the succeeding stack is held against shoulder 32. Switch means 165 which actuates the transfer feed chain means is electrically connected to switch means 184 so that when switch bar 183 is depressed the switch means 165 is deenergized so that during formation of a stack the transfer feed means is rendered positively inoperative. Upon release of switch bar 183 by the discharge of the stack the switch means 165 is energized and the transfer feed chain means will become operative when the next box contacts switch arm 164.

Thus, when a formed stack has cleared the pathway by movement thereof outwardly through the stack discharge opening upon the discharge conveyor means, the box feed switch means 160 (arm 161 being already depressed by a box) is automatically energized to push off another box from stop shoulder 32 onto the transfer feed means for commencing accumulation of boxes in the stacking pathway. The stack-forming operation is repeated as above described.

Modified transfer feed means In Fig. 12 is illustrated a modification of the transfer feed means 17 for advancing a box into receiving station 45R),

Transfer feed means 200 includes an endless chain feed means 201 which may be of any selected length in order to advance a box to a position with its front face in contact with an upstanding box contact element 202 provided on a reciprocally movable box support bar 203. The endless chain means 201 may be the main feed conveyor means for advancing boxes to the stacking mechanism or it may be a relatively short chain means such as shown and described in the prior modification having a length slightly greater than a box to be stacked. The chain means may be driven by any suitable driving mechanism as described in the prior modification.

In this modification means for reciprocally advancing and retracting the box support bar 203 into the receiving station R comprises a double-acting fluid pressure- (such as air) cylinder means 204 lying below and parallel to the support bar 203. A piston rod 205 projecting forwardly from the front end of the cylinder means 204- 111 may be pivotally connected as at 206 to a depending bracket 207 provided on bar 203 adjacent to the forward end thereof; The cylinder means 204' is provided with connections for fluid 208 and 209' at opposite ends thereof'for introduction of fluid under pressure to opposite sides of the piston head carried by the piston rod 205 within the cylinder. may communicate with a double-acting solenoid valve 210 which is actuated by switch means as later described. I One end of the cylinder means 204 may be pivotally con-' nected as at 211 to an upstanding bracket 212 which may be selectively mounted in a plurality of longitudinally spaced holes 213 provided in a support member 214 carried by the frame. Forward travel of'the piston is thus limited and adjusted so as to selectively longitudinal ly position a box within receiving station R.

In operation a box advanced along the conveyor means 201 is urged into abutment with the upstanding box element 202 carried by bar 203. In this position of the box the switch means 165' is energized so that the double-acting solenoid valve is actuated for introducing fluid under pressure through connection 209 to the cylinder means. The piston rod and bar 203 are thereby forced forwardly for advancing the box into the receiving station. The piston head in the cylinder may bottom on the forward wall of the cylinder means to provide a limit to the forward travel of the bar 203. When the box positioned in the receiving station has been engaged and lifted by the elevator means in the manner similar to that described in the prior modification, a switch '215 carried by one of the columns is actuated by a rising box'sup-' port means 110. Actuation of switch means 215 causes the double-acting solenoid valve 210 to introduce fluid under pressure through connection 208 to the forward 1 end of the cylinder means 204 to retract the bar 203.

For safety purposes, a box will not be pushed from' shoulder 32 for feeding to the bar 203 until a safety switch 216 is contacted by a tail extension 217 carried by the bar 203. Upon contact of this safety switch 216 by the tall 217 the switch means 160' for the air cylinder The fluid connections 208 and 209" 33' is unlocked so that the next box may be pushedfrom shoulder 32 for advancement to the box support bar 203.

Top down feed means In Fig. 14 a top down feed means is generally illus-- trated whereby boxes may be intermittently fed to the elevator means at a receiving station positioned adjacent the top of said elevator means. Such a top down feed means may be desirable when feeding boxes from a second floor for stacking and discharge in stacks from a first floor. In this arrangement the elevator means moves only downwardly in the stacking pathway and a plurality of boxes to be stacked are accumulated thereon in its downward movement in spaced relation. Upon reaching the first floor the lowermost box is'deposited'upon discharge feed conveyor means which extends into said pathway and which are operable in the same manner as described in the prior modification.

The top down box feed means includes an infeed chain means 230 for advancing boxes along a horizontal path which lies below the top of columns and slightly below the top sprockets of the endless chain elevator means so that box support means carried by said chain means will be in box support position at approximately the plane of the horizontal path.

Boxes advancing along the infeed chain means 230 are controlled and stopped by shoulder means (not shown) such as described in the prior modification. box is pushed off such shoulder means it is advanced upon a box support bar 231 which may be reciprocally advanced and retraced into receiving station-R by cylinder means such as described in Figs. 12 and 13; The box support bar 231 includes a front pair of laterally extending guide pins 232 and a rear pair of laterally' extending guide pins 233. The guide pins 232' and 233 Whena are slidably movable in guide grooves 234 provided in a pair of opposed parallel longitudinally extendingguide members 235, said guide members being supported in any suitable manner'by stack frame means.

The guide grooves 234 are so constructed that the'box support bar 231 will be lifted asit isadvanced' into the receiving station and then lowered so that a box carried thereby will be lowered upon box support means 110. Further movement of the box support bar 231 will cause the bar to drop below the bottom surface ofa box and then be retracted from beneath the box before the box is caused to move downwardly by actuation of the elevator chain means 80. To accomplish this result,

the guide grooves 234 include a horizontal portion 245' extending for the entire length of' the guide members and lying in a plane which will permit retraction of the guide bar from beneath the box. Intermediate ends of the horizontal groove portion 245 a top pivoted switch or gate member 236 is provided whereby the front pins 232 will be caused to move forwardly up an in'clined guide groove portion 237. When the front pins 232 reach point 238 at the end of said upwardly inclined guide groove portion 237 the pins are guided along a downward inclined advancing groove portion 239 which merges with the forward end of the horizontal groove portion 245.

When the bar 231 is in its rearmost position with the forward pair of pins 232 positioned rearwardly of the gate member 236 the bar will be raised during its advancement as the pins 232 climb the inclined groove portion 237. When the pins reach point 238 the bar and box have advanced into the receiving station R and the box is positioned slightly above the box support means 110. As the bar is lowered because of the movement of the pins 232 down the inclined portion 239 the box comes to rest upon the box support means 110. Further movement of the pins 232 along the downwardly inclined portion 239 will drop the bar below the box and box support members 110 to afford clearance for retraction thereof. As the pins 232 retract along horizontal groove portion 235 they pass beneath the hinged gate member 236 and into the rearmost portion of the guide groove 235. The bar 231 then is fully retracted and is ready to receive another box.

It will thus be readily apparent that the stacking mechanism of this invention contemplates feeding of boxes into elevator means either intermediate ends of said elevator means or at one end thereof. The top down feed mechanism provides a simple effective arrangement 1 for bringing boxes to the top of the elevator means and positioning the boxes for intermittent downward move- It is understood various modifications and changes may be made in the mechanism described and all such changes coming within the scope of the appended claims are embraced thereby.

I claim:

1. In a stacking mechanism: frame means providing a vertical pathway for boxes to be stacked; means providing a receiving station for introducing boxes to said pathway intermediate ends of said pathway; means for successively feedingboxesto said receiving station; means carried by the frame means to move said boxes as received in spaced --relationalong said pathway in one Since boxes are moved a minimum distance for anemia direction away from said receiving station to accumulate a selected number of boxes to be stacked; a stack discharge opening provided by said frame means; a stack discharge conveyor means extending through said opening across said pathway; means for reversing direction of movement of said boxes carried by said moving means to move said boxes toward said discharge conveyor means whereby a first box is deposited on said discharge conveyor means and the remainder of said boxes are stacked one upon the other to form a stack; and means operative after said stack is formed to actuate said discharge conveyor means to move said stack through said stack discharge opening.

2. A stacking mechanism as defined in claim 1 including alignment means pivotally mounted on said frame means for exerting lateral pressure on said boxes upon reversal of direction of movement of said boxes.

3. In a stacking mechanism: frame means providing a vertical pathway for boxes to be stacked; means providing a receiving station for introducing boxes to said pathway; means for successively feeding boxes to said receiving station; means carried by the frame means to move said boxes as received in spaced relation along said pathway in one direction away from said receiving station to accumulate a selected number of boxes to be stacked; a stack discharge opening provided by said frame means; a stack discharge conveyor means extending through said opening across said pathway; means for reversing direction of movement of said boxes carried by said moving means to move said boxes toward said discharge conveyor means whereby a first box is deposited on said discharge conveyor means and the remainder of said boxes are stacked one upon the other to form a stack; and means operative after said stack is formed to actuate said discharge conveyor means to move said stack through said stack discharge opening.

4. In a stacking mechanism: frame means providinga vertical pathway for boxes to be stacked; means pro viding a receiving station in said pathway for introducing boxes to said pathway; means for successively feeding boxes to said receiving station; means carried by the frame means to move said boxes in spaced relation along said pathway in one direction away from said receiving station to accumulate a selected number of spaced boxes to be stacked; a stack discharge opening provided by said frame means; a stack discharge conveyor means extending through said opening across said pathway for seating of a bottom box of said accumulated boxes for starting a stack; and means operative after said stack is formed to actuate said discharge conveyor means to move said stack through said stack discharge opening.

5. In a stacking mechanism for boxes and the like, the combination of: frame means providing a pathway for boxes to be stacked; means for successively feeding boxes to said pathway; means carried by said frame means for supporting and moving said boxes in spaced relation in one direction along said pathway to accumulate a selected number of boxes to be stacked; means operative to reverse direction of movement of said boxes along said pathway when a selected number of boxes is accumulated; stack discharge conveyor means extending into said pathway to stop movement of the adjacent end box of the accumulated spaced boxes and to support said boxes during stack forming by movement of boxes into abutting contact; and means operative after said stack is formed to cause said discharge conveyor means to move said formed stack out of said pathway.

6. A stacking mechanism as defined in claim 5 including means on said frame means operative upon reversal of said direction to exert lateral pressure on said boxes to align said boxes for stacking.

7. In a stacking mechanism, the combination of: frame means defining a vertical pathway for boxes to be stacked; means to successively feed boxes to said pathway; means carried by the frame means to support and move said boxes along said pathway in spaced relation to 21001113111 late a selected number of spaced boxes to be stacked; stack discharge conveyor means extending into said pathway to stop movement of an end box along said pathway to cause forming of a stack by continued movement of the remaining boxes toward said stopped end box; and means operative after the stack is formed for causing said discharge conveyor means to move the stack from said pathway.

8. A stacking mechanism as defined in claim 7 including means to stop feeding of boxes to said pathway when a selected number of boxes to be stacked is carried by said box-moving means.

9. A stacking mechanism as defined in claim 7 including means carried by said frame means and movable to laterally align said boxes. during downward stacking movement of the boxes.

10. A stacking mechanism as defined in claim 7 wherein said feed means is positioned at one end of the said vertical pathway.

11. A stacking mechanism as defined in claim 7 wherein said feed means is positioned at the top end of said vertical pathway.

12. A stacking mechanism as defined in claim 7 wherein said feed means includes a box-carrying bar, and cam means for moving said bar upwardly during advancement thereof to said pathway to deposit a box on the box-moving means and downwardly and rearwardly to retract said bar from said pathway.

13. In a stacking mechanism: frame means providing a vertical pathway for boxes to be stacked; means providing a receiving station for introducing boxes to said pathway; means for successively feeding boxes to said receiving station; said feed means including a reciprocally movable box-carrying bar and fluid pressure means for advancing and retracting said bar to and from said receiving station; means carried by the frame means to move said boxes as received in spaced relation along said pathway in one direction away from said receiving station to accumulate a selected number of boxes to be stacked; a stack discharge opening provided by said frame means; a stack discharge conveyor means extending through said opening across said pathway for seating of a bottom box of said accumulated boxes for starting a stack; and means operative after said stack is formed to actuate said discharge conveyor means to move said stack through said stack discharge opening.

14. In a stacking mechanism, the combination of: stack frame means comprising spaced parallel vertical columns defining therebetween a pathway for boxes to be stacked and providing a box-receiving opening and a stack discharge opening; means to intermittently feed boxes through said box receiving opening into said pathway and including a reciprocally movable box-supporting bar; means carried by said columns for supporting and moving in spaced relation in said pathway boxes fed through said receiving opening, said box moving means including freely pivotally mounted box support means extending into said pathway for releasable supporting engagement with bottom margins of the boxes; and means to stop movement of the lowermost box to cause the remaining boxes to stack thereupon and upon one another; said pivotally mounted box support means including a normally horizontal flat surface for support of said boxes and an inclined wedge surface for contact with a top edge of a lower adjacent box to urge said box support means from box support position during stacking.

15. In an elevator means for a stacking mechanism to accumulate in spaced relation a selected number of boxes to be stacked along a pathway and to stack said boxes in the same pathway, comprising, in combination: opposed endless chain means having adjacent lays movable in the same direction; spaced box support means carried by each chain means in alignment for supporting boxes, each box support means comprising a pair of triangular side members each pivotally connected to one of a pair of chain means and a cover member extending between said side members and providing a normally horizontal flat. surface for engagement with bottom margins of a box and a downwardly and outwardly inclined wedge surface for' sliding engagement with the top edge of an adjacent lower box during stacking; and means on the side members engageable with the adjacent lay of the chain means to limit pivotal movement of said box support.

16. In an elevator means for a stacking mechanism to accumulate in spaced relation a selected number of boxes to be stacked along a pathway and to stack said boxes in the same pathway, comprising, in combination: opposed endless chain means having adjacent lays movable in the same direction; and spaced box support means carried by each chain means in alignment for supporting boxes, each box support means comprising a pair of triangular side members each pivotally connected at a lowermost apex thereof to one of a pair of chain means and a cover member extending between said side members and providing a normally horizontal flat surface for engagement with bottom margins of a box and a downwardly and outwardly inclined wedge surface for sliding engagement with the top edge of an adjacent lower box during stack- 17. A feed means to position a box in a receiving station of a box stacking mechanism comprising the combination of: an elongated member to support a box in said receiving station in one position, said member including means to longitudinally position a box thereon; frame means mounting said member for reciprocal longitudinal movement in and out of said receiving station; and means including an intermittently driven chain means to move a box and said member into said receiving station.

18. In a box stacking mechanism the combination of: upstanding frame means providing a single vertical pathway for movement of boxes therealong; means carried by the frame means to support and to accumulate in spaced relation a plurality of boxes in'said pathway prior to stacking; feed means to intermittently introduce and position each of said boxes in said pathway until supported by said box support means, said feed means including a lon-' gitudinally reciprocal member movable into and out of said pathway; and means in said pathway to stop movement of a box therein to cause stacking of the remainder of said boxes thereupon to form a stack.

19. A box stacking mechanism as stated in claim 18 wherein said means to stop one of said boxes to cause stacking of said boxes comprises a discharge conveyor means operable to remove a stack of boxes from said pathway; 7

20. In a stacking mechanism the combination of: frame means defining a single vertical pathway for boxes to be stacked; means provided by the frame means defining an opening to receive individual boxes in said pathway and an opening to discharge boxes inthe form of a stack; means carried by the frame means to support and move individual boxes along said pathway in spaced relation to accumulate a selected number of spaced boxes to be stacked; and means extending into said pathway at the bottom of the discharge opening to stop movement of an end box along said pathway to cause forming of a stack by continued movement of the remaining boxes toward said stopped end box, said means extending into said pathway serving to move the stack of boxes through the discharge opening after the stack is formed.

21. In a stacking mechanism the combination of: frame means providing a single vertical pathway to receive and to stack aplurality of boxes; elevator means supported from the frame means to support and move boxes along the pathway in spaced relation to accumulate a selected number of spaced boxes to be stacked; means in said pathway to stop movement of an end box along said pathway to cause formation of a stack by continued movement of the remaining boxes toward said stopped'end box; and means operative to discharge the stack from the pathway after the stack is formed.

22. In a box stacking mechanism the combination of:

vto form a stack; and means to actuate said longitudinally reciprocal member comprising a fluid pressure cylinder means positioned below and parallel to said reciprocal member and including a piston rod connected to said reciprocal member adjacent the forward end thereof.

23. In a box stacking mechanism, the combination of: upstanding frame means providing a single vertical pathway for movement of boxes therealong; elevator means carried by the frame means to support and to accumulate in spaced relation a plurality of boxes in said pathway prior to stacking; feed means to move in a feeding direction each box individually into said pathway until supported by said box support means, said feed means including a feed member movable in said feeding direction to place a box in said pathway and movable out of said pathway; means in said pathway to stop movement of a box therein to cause stacking of the remainder of said boxes thereupon to form a stack; and means to actuate said movable feed member comprising a fluid-pressure cylinder means operatively connected with said feed member for actuation thereof.

24. In a box stacking mechanism, the combination of: upstanding frame means providing a single vertical pathway for movement of boxes therealong; means carried by the frame means to support and to accumulate in spaced relation a plurality of boxes in said pathway prior to stacking; feed means to intermittently introduce and position each of said boxes in said pathway until supported by said box support means, said feed means including a feed member movable into said pathway in a feeding direction and movable out of said pathway after a box is supported by said box support means; means in said pathway to stop movement ofa box therein to cause stacking of the remainder of said boxes thereupon to form a stack; and means operative to discharge the stack from the pathway after the stack is formed.

References Cited in the file of this patent UNITED STATES PATENTS 236,485 Conner Ian. 11, 1881 835,312 McNabb Nov. 6, 1906 1,586,544 White June 1, 1926 1,950,943 Hutchinson Mar. 13, 1934 2,017,462 ,Kleineberg Oct. 15, 1935 2,193,264 Bashore Mar. 12, 1940 2,274,842 McCann Mar. 3, 1942 2,324,930 Ioa July 20, 1943 2,325,889 Thompson Aug. 3, 1943 2,550,587 Neja Apr..24, 1951 2,595,437 Aberle "May 6, 1952 2,602,554 Griffith July 8, 1952 2,609,111 Daves Sept. 2, 1952 

